One in eight U.S. women will be diagnosed with breast cancer in her lifetime, and breast cancer is one of the top two causes of cancer death among U.S. women in all racial categories. For women at elevated risk due to strong family history of the disease or certain mutations of the BRCA1 or BRCA2 genes, lifetime risk can be 60% or higher. Several effective biomedical mechanisms have been developed to prevent breast cancer among women at elevated risk, but they are utilized far less frequently - and sometimes by different women - than the medical literature would recommend (Ozanne & Esserman 2010; Tuttle et al. 2010). Fewer than 1% of U.S. women use tamoxifen for chemoprevention, for instance, even though over 15% are at elevated risk for invasive breast cancer and tamoxifen reduces this risk by half (Fisher et al. 1998; Freedman et al. 2003; Waters et al. 2010). Bilateral prophylactic mastectomy is chosen by only a fifth of mutation carriers, for whom it is considered a clinical option, but is also undergone by many women at lower levels of risk, for whom it is unlikely to reduce risk (Friebel et al. 2007; McLaughlin et al. 2009; Tuttle e al. 2010). It is simultaneously unknown why women make the choices they do, and evident that women rarely receive the systematic information and support that would allow them to make educated, health-protective choices fully aligned with their own preferences. Missing from our ability to effectively leverage available methods of prevention is an understanding of the decision-making processes women utilize in the time between learning that their risk is elevated and choosing a course of preventive action. Absent this link, we do not know (a) how women decide among the prevention pathways available; (b) to what degree they are able to implement choices that reflect accurate knowledge and their own preferences; (c) what motivations, interactions, and constraints most forcefully shape their choices; (d) how the features of decision-making affect physical and psychosocial health; or (e) how these dynamics vary across sub-groups defined by race-ethnicity, socioeconomic status, and severity of breast cancer risk. The proposed K01 research will be the first to start from the personal accounts of White and African American women at elevated risk, and trace the full range of dynamics by which they navigate pathways to all potential prevention behaviors. By revealing women's decision-making processes and their effects, this project will illuminate modifiable target points for tailored decision support interventions. Such interventions can empower women to implement health-protective decisions that reflect their own preferences by providing high quality information, interaction, and support. The project will also generate significant public health impact by supporting decision making that leads to better physical and psychosocial health outcomes, and more cost- effective use of biomedical risk-reduction mechanisms. The proposed study is the first stage of a research agenda to understand and support women's decision making in the area of breast cancer prevention. It will explore the processes through which women deliberate and decide among their prevention options, the choices they make as a result, and the effects of not only prevention choices but also the preceding decision-making processes on women's physical and psychosocial well-being. To achieve these goals, it will utilize original data to be collected during the K01. In-depth, semi- structured interviews will be used to generate a thorough understanding of women's decision-making processes, and to generate specific hypotheses about the key decision-making factors that shape prevention choices, and the effects of both decision-making factors and prevention behavior choices on health. Original survey data will be used to test these hypotheses. This application for the NCI Mentored Research Scientist Development Award to Promote Diversity also proposes a structured program of training necessary for the candidate to build the new substantive and methodological proficiencies she will require to undertake the innovative proposed research. This K01 will build on the candidate's existing expertise in medical sociology and qualitative health research through formal training and mentoring in cancer prevention and cancer health disparities, decision science, advanced methods of biostatistical analysis, and the design of interventions to support patient decision making. The highly qualified team of mentors and consultants come from the fields of public health, nursing, breast surgery, clinical genetics, and biostatistics, reflecting a strong multi-disciplinary approach to supporting the complex prevention decisions of women at elevated risk for breast cancer. In sum, this K01 will fill a critical gap in our understanding of breast cancer prevention by investigating the causes and effects of women's prevention choices, and will include the training and research experience necessary to establish the candidate as an independent investigator in the areas of cancer prevention, health disparities, decision science, and intervention research.